The invention relates to a hydraulically actuable releaser for a motor vehicle friction clutch.
A hydraulically actuable releaser for a motor vehicle friction clutch is known from DE-U-84 22 431. The releaser comprises an annular cylindrical slave cylinder of which the casing contains a pressure chamber which is limited radially inwardly by an internal wall and radially outwardly by an external wall extending at a radial distance from the internal wall. Between the internal wall and the external wall there extends an axially movable annular piston which carries a release bearing at its end axially remote from the pressure chamber and adjoins a groove sealing ring via a supporting ring at its end close to the pressure chamber. The groove sealing ring has, on its side axially remote from the annular piston in the region of its internal periphery and its external periphery, sealing lips which enclose an annular groove between themselves and, for sealing the pressure chamber, rest on the internal wall and the external wall.
With the known releaser, the supporting ring is to fill the space between internal wall and external wall without gaps so that the groove sealing ring consisting of elastic material cannot be urged into a gap under pressure loading.